Cardiovascular Journal of Africa: Vol 32 No 5 (SEPTEMBER/OCTOBER 2021)

CARDIOVASCULAR JOURNAL OF AFRICA • Volume 32, No 5, September/October 2021 262 AFRICA this, the American Heart Association and American College of Cardiology (AHA/ACC) developed guidelines in 2014 that stage severity of rheumatic valvular heart disease (based on symptoms at presentation and pre-operative echocardiography findings). 9 These guidelines were updated in 2017 to recommend appropriate evidence-based management strategies. 10 It is unclear whether the AHA/ACC guidelines for valvular heart disease were utilised for stratification of patients presenting for surgery at a major hospital as records had insufficient data to make conclusions. This study undertook to describe the profile of adult patients presenting for rheumatic mitral valve surgery at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH), a tertiary hospital of the University of the Witwatersrand in Johannesburg, South Africa. Methods The study was conducted in the Cardiothoracic Unit and the Department of Anaesthesiology at CMJAH, affiliated to the Faculty of Health Sciences of the University of the Witwatersrand. Approval was obtained from the Human Research Ethics Committee (Medical) of the University of the Witwatersrand and other relevant authorities. A retrospective review was conducted of pre-operative anaesthetic, cardiology and cardiothoracic surgery records belonging to patients who presented for mitral valve surgery from January 2014 to December 2015. Reviewed variables were age, race, gender, pre-operative vital signs, cardiovascular examination data focusing on the presence or absence of arrhythmias, congestive cardiac failure and infective endocarditis, liver and renal function tests, and pre-operative echocardiographic parameters. Relevant variables were then used to stratify patients according to the AHA/ACC guidelines for valvular heart disease. Demographic data, including ethnicity, were collected from hospital records as these were self-reported. These were utilised to classify patients into ethnic groups. All data were collected by one author (NM). A data-collection flow chart is shown in Fig. 1. Descriptive statistics were used, reported as numbers and percentages, means and standard deviations or medians and interquartile ranges, depending on the distribution of data. Results One hundred and two records were eligible for review and 89 patients were enrolled. Thirteen subjects were excluded due to missing vital data. The mean (SD) age of presentation was 42 (12) years, ranging from 18 to 72 years. Of the 89 patients, each had different data sets available for review. The patient demographics and cardiovascular examination findings are illustrated in Table 1. Records of results of pre-operative liver and renal function parameters were available in 51 and 58% of patients, respectively. They were all normal (Table 2). The predominant mitral valve lesion, as diagnosed on echocardiography, showed that 57% (47 patients) of study patients had mitral regurgitation (MR) and 42% (35 patients) had mitral stenosis (MS). Two study patients presented with mixed mitral valve disease with predominant regurgitation and were therefore classified under regurgitation as per the AHA/ACC guidelines for valvular heart disease. Combined echocardiographic results for MR and MS are shown in Table 3. The MR patients had mean (SD) left atrial size of 55 (13) mm for females and 49 (6) mm for males. The mean (SD) for PAP was 55 (21) mmHg, mean (SD) LVEF was 59% (11) and Total number reviewed n = 102 Included n = 89 Demographics n = 89 Cardiovascular examination n = 81 (arrhythmias, congestive cardiac failure, infective endocarditis) Pre-operative renal blood-work n = 52 Pre-operative liver blood-work n = 45 Pre-operative echocardiographic records n = 82 Left ventricular ejection fraction n = 82 Left ventricular systolic diameter n = 71 Pulmonary artery pressure n = 67 Left atrial size n = 64 Mitral valve area n = 42 Effective regurgitant orifice n = 10 Parameters used for patient stratification according to AHA/ACC guidelines for valvular heart disease Parameters analysed Excluded n = 13 missing data Fig. 1. Flow chart indicating variables collected for the study. AHA/ACC, American Heart Association/American College of Cardiology. Table 1. Demographic and cardiovascular examination findings of study patients Variables Frequency, n (%) Gender, n = 89 Female 52 (58) Male 37 (42) Ethnicity, n = 89 Black 67 (75) White 16 (18) Other 6 (7) Pre-operative cardiovascular examination findings, n = 85 Yes No Arrhythmias 39 (46) 46 (54) CCF 42 (49) 43 (51) IE 10 (12) 75 (88) CCF, congestive cardiac failure; IE, infective endocarditis. Table 2. Pre-operative liver and renal parameters Tests Interquartile range Median Liver function test (mmol/l), n = 45 Alkaline phosphatase 66 32–95 Gamma glutamine transferase 48 27–82 Alanine transaminase 52 28–111 Aspartate transaminase 45 29–83 Renal function test (mmol/l), n = 52 Urea 5.8 5.1–8.4 Creatinine 83 68–105